What is the fastest way to combine two xml files into one

Question

If I have two string of xml1 and xml2 which both represent xml in the same format. What is the fastest way to combine these together? The format is not important, but I ju

Answer 1

If you can guarantee this format you can combine them by doing string manipulation:

• Read the first file, keep everything before ""
• Read the second file, remove the part up to ""
• Combine those strings.

This should be the fastest way since no parsing is needed.

const string RelevantTag = "AllNodes";

string xml1 = File.ReadAllText(xmlFile1);
xml1 = xml1.Substring(0, xml.LastIndexOf(""));

string xml2 = File.ReadAllText(xmlFile2);
xml2 = xml2.Substring(xml.IndexOf("<" + RelevantTag + ">") + "<" + RelevantTag + ">".Length, xml1.Length);

File.WriteAllText(xmlFileCombined, xm1 + xml2);

That said I would always prefer the safe way to the fast way.